The role of infectious agent in development of tooth decay

Aim: to assess the relationship between colonization of the oral cavity with S. mutans and different genotypic characteristics and the degree of tooth decay in children.Materials and methods. 274 children aged 5 to 17 years (153 girls and 121 boys) who received a preventive dental checkup were included in the study. The dental caries experience was assessed by the DMFT index (number of decayed, missing due to caries, and filled teeth), according to WHO recommendations. The plaque was collected with sterile wooden toothpicks from the buccal gingival margin or from fissures of the first molars and placed in 1.5 mL Eppendorf tubes, and then plated on Mitis Salivarius Agar medium (HiMedia, India). 481 strains of S. mutans were selected for further study. DNA was extracted by an express method. Amplification was performed in the CFX-96 thermal cycler (Bio-Rad, USA). Serotyping was performed by multiplex PCR. PCR products were analyzed by gel electrophoresis in 1.5% agarose gel with ethidium bromide (10 mg/mL) manufactured by Helicon, Moscow, and visualized in UV light in transilluminator UVT1 by Biokom. Genotyping was performed according to the methodology (Saarela et al., 1996) with the oligonucleotide primer OPA-02 (5’-TGCCGAGCTG-3’). Strains of S. mutans were studied for the presence of the following genes: gtfB, spaP, cnm, fruA, gtfB, htrA, comE, mutA x(I), mutA (II), mutA (III), nlmAB (IV), adcA, Smu.399, Smu.583, Smu.761, Smu.940c, Smu.1449, Smu.2130.Results. S. mutans was isolated from all the examined children. Dental decay was detected in 82.4% of the children. Among the strains studied, all 4 serotypes were found: in children with a DMFT = 0 only serotypes k and f were detected; the predominant serotype in children with tooth decay was serotype c (74.7%). 19 genotypes of S. mutans were identified. In children without caries (DMFT = 0), S. mutans did not contain the genes spaP, comE, adcA, Smu.2130, Smu.1449, gtfB, htrA. With the increase in the DMFT index, the frequency of their detection increased. 9 genotypes of S. mutans had all 7 virulence factors. In 94.9% of children colonized by these “virulent” genotypes, high DMFT index scores were observed.Conclusion. The data obtained indicate that only a limited number of specific strains have a cariogenic potential. Strains of S. mutans belonging to serotypes e and c with a combination of virulence genes spaP, gtfB, comE, adcA, Smu.2130, Smu.1449, and htrA were isolated from children with tooth decay. Strains without these factors did not cause any damage to the teeth. The degree of tooth decay increases with colonization by several genotypes with the combination of virulence factors described above

БАКТЕРИОФАГИ КАК ЭФФЕКТИВНЫЕ ПРОТИВОЭПИДЕМИЧЕСКИЕ СРЕДСТВА ДЛЯ КУПИРОВАНИЯ ВСПЫШЕК ВНУТРИБОЛЬНИЧНЫХ ИНФЕКЦИЙ

Antibiotic resistance threatens the effective prevention and treatment of healthcare associated infections which are the most frequent adverse event in health-care settings worldwide. There is an urgent need to investigate alterative preventive and treatment options while there are still a few antibiotics left. Bacteriophage (phage) therapy has been championed as a promising alternative to antibiotics.The aim of this study was to evaluate the efficacy of a therapeutic bacteriophages to control of Staphylococcus aureus and Klebsiella pneumonia outbreaks in newborn intensive care units.Materials and methods. Commercial bacteriophage cocktails targeting these paphogens was orally and locally given over 5 days to patients of neonatal intensive care units in Saint-Petersburg, Russia.Results. Bacteriophages were used as antimicrobial agents for control of three S.aureus outbreaks and one K.pneumonia outbreak. S.aureus infection incidence during the three outbreaks were 22.2%, 54.5% and 50.0% accordingly, and K.pneumoniae outbreak – 19.0%. After application of the phage cocktails among newborns, the incidence of infections caused by S.aureus and K. pneumoniae decreased to zero. All treatments were well tolerated. No adverse events were reported.Conclusion. Presented results clearly demonstrate high efficiency of bacteriophages. Phages have several features that make them potentially attractive antibacterial agents. Bacteriopahges are highly specific and very effective in destroying targeted bacteria, have only minimally impact on health-protecting normal flora bacteria, safe and rapidly modifiable to combat the emergence of newly arising bacterial threats.Инфекции, связанные с оказанием медицинской по- мощи, являются одной из наиболее значимых проблем современного здравоохранения. Неуклонно растущая устойчивость возбудителей этих инфекций к антибиотикам диктует необходимость использования альтернативных способов борьбы с ними. В качестве таких средств могут выступать бактериофаги.Цель: оценка противоэпидемической эффективности бактериофагов как средств для купирования вспышек в отделениях реанимации новорожденных.Материалы и методы. Для фаготерапии использовались моно- или комбинированные препараты бактериофагов ФГУП «НПО «Микроген». Бактериофаги при- меняли в течение 5 дней местно и перорально путем введения в питательную смесь.Результаты. Бактериофаги использовались для купирования трех вспышек, вызванных S. aureus, и одной вспышки, вызванной K. pneumoniae. Частота внутри- больничного инфицирования S. aureus в ходе трех вспышек составляла 22,2%, 54,5% и 50,0% соответственно, при вспышке K. pneumoniae – 19.0%. После применения бактериофагов по описанной схеме частота инфекций, вызванных данными возбудителями, снизилась до нулевых значений.Заключение. Результаты данного исследования убедительно свидетельствуют о высокой противоэпидемической эффективности бактериофагов в условиях вспышек внутрибольничных инфекций. Ряд свойств, которыми обладают бактериофаги, в частности высокая специфичность в отношении конкретных возбудителей инфекций, дает им преимущество перед другими антибактериальными средствами

Atropisomerism of phosphorus-containing N-aryl carbamates. Experimental and computational data

Studies by 1H NMR spectroscopy and X-ray diffraction analysis revealed hindered rotation of the aromatic substituent about the C Ar-N bond in ortho-substituted (except for o-fluorine-substituted) phosphorus-containing carbamates. The energy barriers to rotation (AG c ≠) and coalescence temperatures (Tc) determined by the coalescence method increase with increasing volume of the ortho substituent. Conformations resulting from rotation of the ortho-substituted aryl group about the CAr-N bond were analyzed by quantum-chemical methods, potential curves were constructed, and differences between the conformational energies and the heights of rotation barriers were estimated. The theoretical rotation barriers change in parallel with the experimental values of ΔGc ≠ however, the theoretical values are much smaller in magnitude

Resource potential of some species of the genus Miscanthus Anderss. under conditions of continental climate of West Siberian forest-steppe

In the meantime, search for environmentally friendly renewable energy sources alternative to fossil fuel has been driven by energy security challenges including limited availability of fuel and energy price fluctuations. Therefore herbal perennial grasses with their rapid growth and prominent biomass yield increasingly make it a favorite choice as a valuable agricultural crop usable for cellulosic ethanol production. As an example, the genus Miscanthus Anderss. (silvergrass) comprises ca. 14–20 species including M. sacchariflorus (Maxim.) Hack., M. sinensis Anderss., M. purpurascens Anderss, and M. × giganteus, which appear to be an almost inexhaustible source of sustainable raw material, and several Miscanthus species were investigated as a potential biofuel energy crop with commercially viable way of its producing. Introduction and investigation of Miscanthus species were initiated in the Central Siberian Botanical Garden of the Siberian Branch of the Russian Academy of Sciences (CSBG SB RAS, Novosibirsk, Russia) based on the grass and ornamental plant collection in the late 1990s. The paper objective is studying the biological traits of three Miscanthus species introduced into the CSBG SB RAS, selection and genetic identification of cultivars and varieties as the most perspective agricultural crop. To evaluate the potential crop yield and selection prospects of Miscanthus species being competitive as a valuable biofuel energy crop, the authors have estimated seasonal rhythms of model species development in the continental climate conditions of West Siberia. The article characterizes different Miscanthus varieties obtained either by the ex situ or in situ methods; presents the biochemical analysis of plant material and molecular identification of three Miscanthus species introduced into the CSBG SB RAS. The seasonal development analysis of three selected varieties of Miscanthus (M. sacchariflorus, M. sinensis, and M. purpurascens) proved the hydrometeorological conditions to be advantageous for prominent biomass yield, e. g. contributory to use Miscanthus in West Siberia as an easy to grow cellulose-rich grass. Molecular markers applicable in DNA-identification and genetic passportization of Miscanthus varieties have been established, which are perspective as such an economically available plant material as alternative non-woody source of cellulose

Nanoparticle-Delivered 2-PAM for Rat Brain Protection against Paraoxon Central Toxicity

© 2017 American Chemical Society.Solid lipid nanoparticles (SLNs) are among the most promising nanocarriers to target the blood-brain barrier (BBB) for drug delivery to the central nervous system (CNS). Encapsulation of the acetylcholinesterase reactivator, pralidoxime chloride (2-PAM), in SLNs appears to be a suitable strategy for protection against poisoning by organophosphorus agents (OPs) and postexposure treatment. 2-PAM-loaded SLNs were developed for brain targeting and delivery via intravenous (iv) administration. 2-PAM-SLNs displayed a high 2-PAM encapsulation efficiency (∼90%) and loading capacity (maximum 30.8 ± 1%). Drug-loaded particles had a mean hydrodynamic diameter close to 100 nm and high negative zeta potential (-54 to -15 mV). These properties contribute to improve long-term stability of 2-PAM-SLNs when stored both at room temperature (22 °C) and at 4 °C, as well as to longer circulation time in the bloodstream compared to free 2-PAM. Paraoxon-poisoned rats (2 × LD50) were treated with 2-PAM-loaded SLNs at a dose of 2-PAM of 5 mg/kg. 2-PAM-SLNs reactivated 15% of brain AChE activity. Our results confirm the potential use of SLNs loaded with positively charged oximes as a medical countermeasure both for protection against OPs poisoning and for postexposure treatment

6-methyluracil derivatives as bifunctional acetylcholinesterase inhibitors for the treatment of Alzheimer's disease

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Novel 6-methyluracil derivatives with ω-(substituted benzylethylamino)alkyl chains at the nitrogen atoms of the pyrimidine ring were designed and synthesized. The numbers of methylene groups in the alkyl chains were varied along with the electron-withdrawing substituents on the benzyl rings. The compounds are mixed-type reversible inhibitors of cholinesterases, and some of them show remarkable selectivity for human acetylcholinesterase (hAChE), with inhibitory potency in the nanomolar range, more than 10 000-fold higher than that for human butyrylcholinesterase (hBuChE). Molecular modeling studies indicate that these compounds are bifunctional AChE inhibitors, spanning the enzyme active site gorge and binding to its peripheral anionic site (PAS). In vivo experiments show that the 6-methyluracil derivatives are able to penetrate the blood-brain barrier (BBB), inhibiting brain-tissue AChE. The most potent AChE inhibitor, 3 d (1,3-bis[5-(o-nitrobenzylethylamino)pentyl]-6-methyluracil), was found to improve working memory in scopolamine and transgenic APP/PS1 murine models of Alzheimer's disease, and to significantly decrease the number and area of β-amyloid peptide plaques in the brain. Head-AChE relief! In our efforts to identify compounds to treat Alzheimer′s disease, we found that 1,3-bis[ω-(substituted benzylethylamino)alkyl]-6-methyluracils bind to the active site gorge and peripheral anionic site of acetylcholinesterase (AChE). These compounds can cross the blood-brain barrier, and decrease the number and area of β-amyloid plaques in the brain

Combination delivery of two oxime-loaded lipid nanoparticles: Time-dependent additive action for prolonged rat brain protection

© 2018 Elsevier B.V. A novel approach for brain protection against poisoning by organophosphorus agents is developed based on the combination treatment of dual delivery of two oximes. Pralidoxime chloride (2-PAM) and a novel reactivator, 6-(5-(6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)pentyl)-3-hydroxy picolinaldehyde oxime (3-HPA), have been loaded in solid-lipid nanoparticles (SLNs) to offer distinct release profile and systemic half-life for both oximes. To increase the therapeutic time window of both oximes, SLNs with two different compartments were designed to load each respective drug. Oxime-loaded SLNs of hydrodynamic diameter between 100 and 160 nm and negative zeta potential (−30 to −25 mV) were stable for a period of 10 months at 4 °C. SLNs displayed longer circulation time in the bloodstream compared to free 3-HPA and free 2-PAM. Oxime-loaded SLNs were suitable for intravenous (iv) administration. Paraoxon-poisoned rats (0.8 × LD50) were treated with 3-HPA-loaded SLNs and 2-PAM+3-HPA-loaded SLNs at the dose of 3-HPA and 2-PAM of 5 mg/kg. Brain AChE reactivation up to 30% was slowly achieved in 5 h after administration of 3-HPA-SLNs. For combination therapy with two oximes, a time-dependent additivity and increased reactivation up to 35% were observed

The role of the teacher in the development of personality in learning

The modern system of quality of education in higher educational institutions is focused not only on the assimilation of knowledge by students, but also on the development of cognitive and creative abilities, the formation of personal responsibility and experience of independent activity. In this regard, the role of a higher school teacher in the education of personal qualities of students is relevant. In our work, by questioning the 3rd year students of the medical and preventive faculty, who studied in the 2018-2019 academic year, their attitude to the educational process at the Department of propedeutics of internal diseases is determined. 96% of students described the positive impact of teachers of the Department on the formation of the student's personality. 88% of students noted a very good and 11% – a good impression of communication with teachers. 96% of students highly appreciated the activity of the teacher in increasing the motivation to teach students in the subject. Thus, educational activity at the Department of propaedeutics of internal diseases is highly appreciated by students.Современная система качества образования в высших учебных заведениях ориентирована не только на усвоение студентами знаний, но и на развитие познавательных и созидательных способностей, формирование личной ответственности и опыта самостоятельной деятельности. В связи с этим роль преподавателя высшей школы в воспитании личностных качеств студентов является актуальной. В нашей работе путем анкетирования студентов 3 курса лечебно-профилактического факультета, обучавшихся в 2018-2019 учебном году, определено их отношение к воспитательному процессу на кафедре пропедевтики внутренних болезней. 96% студентов охарактеризовали положительное влияние преподавателей кафедры на становление личности студента. 88% студентов отметили очень хорошее и 11% — хорошее впечатление от общения с преподавателями. 96% обучающихся высоко оценили активность преподавателя в повышении мотивации к обучению студентов по предмету. Таким образом, воспитательная деятельность на кафедре пропедевтики внутренних болезней достаточно высоко оценивается студентами

Prevalence of Markers of Certain Blood-Borne Viral Infections in Pregnant Women and Their Partners in the Republic of Guinea

The aim of the work was to estimate the prevalence of HIV, HBV and HCV markers among pregnant women and their male partners in the Republic of Guinea.Materials and methods. The material of the study was blood plasma samples from 140 pregnant women living in Kindia prefecture and N’Zerekore prefecture, as well as 60 male partners who reported sexual contact with HIV-infected persons. The samples were examined for the presence of serological (HBsAg, HBeAg, antibodies anti-HBs IgG, anti-HBcore IgG, anti-HBe IgG, anti-HCV IgG, Ag/Ab-HIV) and molecular (HBV DNA, HCV RNA, HIV RNA) markers.Results and discussion. The age of the examined pregnant women ranged from 13 to 55 years and was on average (26.29±9.67) years. The age of men varied from 15 to 60 years, on average – (29.05±11.99) years. When assessing the prevalence of serological markers, antibodies to HCV were detected in 2.14 % cases in women and in 3.33 % cases in men. Antibodies to HIV were found in 6.43 % and 6.67 % women and men, respectively. Serological markers associated with HBV were detected in 80.71 % (HBsAg – 13.57 %) of women and 81.67 % (15 %) of men. In the pregnant women, HCV RNA was not detected, HIV RNA was revealed in 1 case, HBV DNA was identified in 26 cases (18.57 %), including 5 % HBsAg-negative hepatitis B cases. In the men group, HCV RNA and HIV RNA were detected in 3.33 % and 6.67 % cases, respectively. HBV DNA was determined in 16.67 % of men, including latent hepatitis B in one person. A significantly higher incidence of HIV in men compared to women is shown (χ2=3.907 at p<0.05). The relative risk of HIV infection in men is nine times higher than in women: RR=9.333; p=0.0291; 95 % CI: 1.065–81.815 %. Four out of five identified HIV infection cases were co-infected with HBV and/or HCV. There is an obvious need to introduce screening for HIV, HCV, HBV, including latent hepatitis B, into routine laboratory diagnostics during examination of pregnant women and their partners, followed by couples counseling and vaccination against hepatitis B virus

Assessment of students’ education quality on practical training

The quality of the educational process is an important component of education in higher education institutions and determines the quality of the final result, i.e. the educational product. Competence approach to the result of education involves taking into account practical skills and the ability to apply the knowledge in practice. Assessing and tracking the quality aspects of learning is an extremely important task. To assess the quality of education at the Department of propedeutics of internal diseases by questionnaire analyzed the satisfaction of students of the 3rd year of medical and preventive faculty educational services in 2018-2019 academic year. Most of the students (90%) rated the organization of the educational process in the discipline as excellent or good. The quality of practical training and the material studied on them by a significant part (70%) of students are evaluated perfectly and well. 94% of students believe that the goals set in the classroom are realized well and perfectly. 90% of students evaluate the development of practical skills on "good and excellent". Thus, the educational process at the Department of propaedeutics of internal diseases fully satisfies students.Качество образовательного процесса является важной составляющей обучения в высших учебных заведениях и определяет качество конечного результата, т.е. образовательного продукта. Компетентностный подход к результату образования предполагает учет практических навыков и умения на практике применять полученные знания. Оценивание и отслеживание качественных аспектов обучения является исключительно важной задачей. Для оценки качества обучения на кафедре пропедевтики внутренних болезней путем анкетирования проанализирована удовлетворенность студентов 3 курса лечебно-профилактического факультета образовательными услугами в 2018-2019 учебном году. Большая часть студентов (90%) оценила организацию учебного процесса по дисциплине как отличную или хорошую. Качество практических занятий и изучаемый на них материал значительной частью (70%) студентов оценены на отлично и хорошо. 94% студентов считают, что поставленные на занятиях цели реализуются на хорошо и отлично. 90% студентов оценивают освоение практических навыков на «хорошо и отлично». Таким образом, учебный процесс на кафедре пропедевтики внутренних болезней полностью удовлетворяет студентов